Episode 4 of Ninja Kamui kicks off with an intriguing twist as Higan receives a mysterious, anonymous call. The caller, whose voice is shrouded in secrecy, warns Higan of the formidable challenge that lies ahead—penetrating the heavily fortified Auza City. The caller reveals himself as a fellow exiled ninja, sharing a similar plight with Higan, and extends a helping hand. He offers invaluable assistance and shares a rendezvous point, inviting Higan to join him if he is intent on completing his mission.
The narrative then pivots to FBI agent Mike, whose mind is clouded by the haunting memory of a past tragedy—the loss of his beloved son. Mike is joined by Emma and Higan, and the trio deliberates on their next course of action, amidst scrutiny from all sides. Emma unearths a clandestine group lurking on the dark web, which has been closely monitoring Auza's operations. Whispers within the digital underworld suggest that Auza is developing weaponry capable of wielding control over entire nations.
Mike, concerned for Emma's safety, implores her to step back from the brink of danger. However, Emma stands her ground, her resolve unwavering. She declares that she cannot stand idly by while Higan and Mike soak up all the glory and shoulder the burden of action.
Elsewhere, the CEO of Auza is impressed but unyielding upon learning of Higan's triumph over their prototype warrior—a formidable creation designed tosingle-handedly fend off an armada. Despite this setback, the CEO remains undeterred and vows to gather more data, ensuring that their prototype warriors will ultimately emerge victorious against Higan.
As for Mike, Master Yamazi holds the conviction that he is merely a mortal, posing no significant obstacle to their meticulously crafted plan. When the fateful moment arrives, Mike can be dispatched with little effort. Moreover, we witness a nostalgic glimpse into the past where, upon the conclusion of their arduous training, Higan, Zhai, and Mari are bestowed with a clandestine art technique, a secret so profound that it must never, under any circumstance, be disclosed to the uninitiated. Notably, Yamazi himself was also a witness to this solemn ceremony.
As the episode unfolds, Higan arrives at the designated rendezvous point and finds himself entangled in another telephonic conversation. The caller, detailing the intricacies of Auza City's security apparatus, reveals a city replete with surveillance cameras, sensitive sensors, and lethal drones, where any trespasser risks instant annihilation. Yet, the caller provides Higan with an unseen pathway to infiltrate the city without leaving a trace.
Furthermore, the caller vows to penetrate the city's internal security network, manipulating the cameras and deactivating the electrical barrier once Higan reaches his destination. Despite the formidable challenge posed by a dozen vigilant guards and a relentless hail of bullets, Higan manages to breach the headquarters' perimeter. However, as he nears the electrical field, a formidable force repels him. In that harrowing instant, he beholds Zhai, standing with an enigmatic presence on the opposite side of the barrier.
